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Old Feb 05, 2013, 02:53 PM
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Help!
Guardian 2D/3D servo jitter problem

I am experiencing some strange servo jitter behavior when control sticks are moved close to neutral position. It doesn't matter if the Guardian is in 2D,3D or even stabilizing off mode. As long as I pass the servo signal from my receiver through the Guardian, servo movement is not smooth for input signals close to neutral. The jitter also affects other channels than the one currently being moved, though not as much as the channel with the moving input.
With slow servos (cheap no-name brand) the effect is hardly noticeable but with fast digital servos the jitter makes me to worried to fly with.
It seems to have to do only with the Guardian reading of input from the receiver as I can only get the jitter by moving the sticks and can not see it for servo movements caused only by the stabilizing.
I'm using a Futaba 2.4ghz system and tried two different receiver types (FASST and FASSTest) and various servos. Without the Guardian connected all other combinations moves smooth also close to center, but with the Guardian connected the jitter happens even if it is in non stabilizing mode.
Any ideas of what is causing my problem or how I can solve it?
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Old Feb 07, 2013, 03:31 PM
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Hi, and sorry to hear about your jitter issue. We're looking into your report, and I'll get back soon.
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Old Feb 11, 2013, 03:18 PM
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Hi, we have been discussing your report here - sorry for delay.

With stabilization disabled, is it possible for you to trim your sticks to a point where the jitter happens without needing to move your sticks to reproduce it?

Also, could you let me know the model number(s) of the receivers you are using?

Finally, if convenient, could you make a short video of the servo movement (with audio) and post it on youtube for us? That would help us to understand better the exact type of jitter you are seeing.
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Old Feb 12, 2013, 01:38 PM
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Here is a video of a test:
Guardian servo jitter problem (1 min 6 sec)

At first smooth movement from the guardian gyro. Then I set it in gyro off mode to just pass through input signal. Moving input close to center is not smooth (it is without the guardian connected).
Servo in this test: futaba S3001
Receiver: futaba R6106HFC 2.4Ghz FASST

I'm not able to set a static input that results in any jitter. It only happens at movement.
It's like input close to center doesn't update the servo position at all and then when input is outside some threshold the servo suddenly catches up with some additional jittery movement.
The servo is not a digital one as the only digital one I have are currently glued in place in my airplane. The digital ones makes it a bit more noticeable. Mainly because they are just responding faster I assume.
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Last edited by SebbeMalm; Feb 12, 2013 at 01:40 PM. Reason: More details
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Old Feb 14, 2013, 02:06 PM
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Hi,

First, thanks for taking the time to set up this repro and video. That makes it very easy to see the issue.

We've been discussing this here and have a couple of theories. If it's convenient, would you be able to try one more test to help us confirm? Assuming the issue happens also with your aileron channel (I believe your demonstration shows the elevator channel) could you disconnect all the cables from your Guardian to receiver except the Aileron, and see if the issue recurs? If it does not, could you add back the channels sequentially, until it reproduces?
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Old Feb 17, 2013, 01:32 PM
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I've been testing some more and found some interesting results. As you anticipated the number of connected channels has an affect. With only aileron connected (that is also no gain, no mode) I'm not able to reproduce it. However by connecting any other input its back. Also with only adding the mode switch the problem is there also for the ailerons.
What I also found was that the jitter happens when two (or more) input channels are at the same value. With only aileron and mod connected I can move the position the jitter happens by changing the center value of the mod input, of corse if I move it to much I also change the mode.
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Old Feb 18, 2013, 06:34 PM
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Hi, and thanks for taking the time!

We've ordered a similar Futaba setup to attempt to reproduce the problem here and get it addressed.
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Old Jun 12, 2013, 02:31 PM
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It's been a while. Any progress on this issue?
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Old Jun 14, 2013, 03:08 PM
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Hi, and sorry for delay. We have not been able to reproduce this problem here, unfortunately. We're going to continue to try, however.
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